Electrical plug device



1935. P. CLARK, JR

ELECTRICAL PLUG DEVICE Filed Nov. 19, 1951 lllll II IIIIII IIIIII Patented Aug. 13, 1935 UNITED STATES PATENT OFFICE The present invention relates to improvements in electrical plug devices, and has for an object to provide a construction in which the plug con tact units may be securely fixedin the plug housing without the use of screws or other extraneous fastening devices, and without the necessity of molding the same into the housing during the molding of the latter. A further object is to provide a structure in which the contact units will be reliably held against, displacement or distortion. Another object is to provide a housing which may be conveniently molded, and which will have the desirable characteristics of light weight, compactness, and strength, and which will at the same time provide ample room for the convenient attachment of wires.

With the above and other objects in view, an embodiment of the invention is shown in the accompanying drawing, and this embodiment will be hereinafter more fully described with reference thereto, and the invention will be fully pointed out in the claim.

In the drawing:

Fig. l is a plan view of the plug housing, ac-

cording to the present embodiment of the invention.

Fig. 2 is a plan view showing the plug housing with the contact units inserted therein, and with the closure diskremoved.

Fig. 3 is a vertical sectional view taken along the line 3-3 of Fig. 2, the contact units-being shown in elevation, and the closure disk being shown in place.

Fig. 4 is a vertical sectional view taken along the line 4-4 of Fig. 2, the closure disk being shown in elevation and a 'pofition of the contact unit being broken away. a v Fig. 5 is a perspective View of one of the contact units of the type illustrated in Figs. 2 to 4.

Fig. 6 is a perspective view of a modified form of contact unit.

Fig. 7 is a plan view of the plug device showing contact units of the type illustrated in Fig. 6 in' place therein. 5 Similar reference characters indicate corresponding parts throughout the several figures of the drawing.

Referring to the drawing, the plug device housing, according to the present embodiment of my invention, is molded from hard rubber, Bake lite", or other suitable material, and is of generally cylindrical hollow form comprising a cylindrical side wall l and a bottom wall or base ll having a transverse channel l2 therein which forms a transverse rib l2' interiorly of the bottom,

an outlet opening I? being provided centrally of the channel through which the lead wire is adapted to be extended. The channel I2 permits this lead wire to be carried laterally to one side or the other, when another plug device is plugged in, and as will hereinafter more fully appear.

Upon the interior of the wall [0 and diametricaliy opposed at each side of the transverse rib there is provided a vertically disposed channel l4 having reta ning flanges l5 and 13 at each side and which extend from the base to a point. substantially spaced below the upper end of the wall end being spaced below the upper end of the wall 15- HIV and form'ng a shouldered support for the closure disk hereinafter more fully referred to. Reinforcing ribs i8 are formed upon the interior of the wall ID at each end of the transverse rib and are provided at their upper ends with reduced vertically disposed ribs l9 having their upper ends spaced below the upper end of the wall it and adapted to support the closure disk at points between the points of support provided by the ribs H. The upper ends of the ribs l8 are spaced substantially below the upper end of the wall It and are adapted to form supports for portions of the Contact units, as will presently more fully appear.

At the lower end of the channels it and in- 80 wardly spaced therefrom, a vertical wall 20 is formed on the base, its ends being connected at one side to the ribs l5 and I6 by reinforcing wall portions 2l2l and being connected at the other side to the transverse rib l2 by somewhat shorter reinforcing. wall portions 22-42. The upper edges of the wall 20 are preferably beveled or chamfered, as at 23, as are also the inner edges of the wall portions 22-22, as at 24. The base II is provided at each side of the rib I2 and between the wall portions 22-22 with a rectangular plug receiving opening or slot 25.

A pair of plug devices or units are secured in the housing, and as shown in the illustrated embodiment, Figs. 2 to 5, each is preferably formed by bending a strip of suitable metal upon itself, as at 26 to form a double thickness substantially rigid plugging portion 21, the outer leg of which is bent outwardly, as at 28, and downwardly. as at 29, the'lower end of the portion 29 being reduced in width by cutting in the edge at the side, as at 30, and being bent inwardly and upwardly, as at 3|, preferably at an angle of less than 45, and having a seriesof sharp toothlike projections 32 at its edge. The inner leg is provided with an oilset bend 33 at a point below the bend of the portion 28, and a single thickness resilient contact portion 34 extends below said bond 33, being diagonally bent at its lower end,

as at 35, to facilitate entry of a plug. The plugging portion 21 is provided near its upper end with a hole 36 and the spring contact portion 34 is provided with a pressed out boss 31, which snaps into the hole .36 of a similar plug unit when the latter is plugged into the device through the slot 25. Upon the portion 28 there is disposed a binding post supporting plate 38 having an arcuate outer edge and a right angular inner edge, and secured to the plugging portion 21 by staking, as at 39. A tapped hole 40, Fig. 4, is' provided at the extended end of the plate 38 and is engaged by a screw 4| which serves as a. binding post for securing the end of a lead wire to the unit.

In the assembled relation the binding post end of the plate 38 is seatedand supported upon the upper end of the rib l8.

In assembling theunits the leg portion 29 is engaged in the channel Hi, the reduced width of the lower bent end portion 3| being slightly narrower than the space between the flanges l5 and I6, so that the portion 28 may be slid downwardly in the channel behind saidflanges l5 and It. The spacing of the wall 20 from the channel is such that the end portion 3|- must be forced into relation with said wall under slight compression, so that its toothed edge 32 will bite into the surface thereof, the angle of said portion 3| being such that upward pull on the plug causes the toothed edge tobite more'flrmly, thus efiectually retaining the device against vertical.

displacement. The channel l4 and the retaining flanges l5 and I6 accurately align the plug devices vertically and prevent any possibility of lateral displacement and distortion.

The plugging portions 21 of the two plug units, are snugly engaged in slots 42 of a closure disk or washer 43 of insulating material fitted within the wall l0 and seated upon the ends of the ribs V I1 and I9, which support the washer at four equally spaced points.

The lead wire 44 is extended through the opening i3 and secured to the binding posts, the arrangement providing ample-room for-attaching itwith facility.

In Figs. 6 and 7 I have shown a modified form of plug and contact unit in which a tapped hole 45 is provided in the lateral portion 28 and is engaged by a binding post screw t6, the lead wires in this case being secured directly to the portion 28.

I have illustrated and described a preferred satisfactory embodiment of my invention, but it is obvious that changes may be 'made therein, within the spirit and scope thereof, as defined in the appended claim.

Having thus described my invention, what I 1 claim and desire to secure by Letters Patent is:-

In an electrical device, an insulating housing having a vertically disposed channel interior-a end walls, said flanges forming opposed vertical grooves at each side of said channel, a contact making member comprising a portion inserted in said channel having vertical marginal edge portions disposed in said grooves and retained against lateral displacement thereby, and a reduced securing flange portion connected to said first mentioned portion extending angularly in the direction opposed to the direction of insertion of said contact member and projecting through the space between said flanges, and a vertical securing wall in said housing laterally opposed to said vertical side wall and bitingly engaged by the edge of said securing flange portion to secure the contact making member in the housing against vertical displacement, said securing flange portion being wedged between said vertical side wall and said vertical securing wall. LANCASTER P. CLARK, JR. 

